Process for the manufacture of synthetic textiles



United States Patent PROCESS FOR THE MANUFACTURE OF SYNTHETIC TEXTILES Hisatomo Fujima, Fukui-shi, and Minazo Yoshida,

' Otsu-shi, Japan 7 Nb Drawing. Application April 18, 1956 Serial No. 578,893

This invention relates to processes for the manufacture of crepe fabrics consisting of synthetic fibers. In particular, it is concerned with processes for producing crepe fabrics from grey fabrics woven of synthetic textile yarns which are made by imparting a high degree of temporary twist to continuous filament yarn, setting the temporary twist by heat treatment, and untwisting beyond the point of zero twist in the opposite direction and then sizing to prevent shrinkage.

The fabrics manufactured by the process of the invention posses not only the strength of synthetic fibers, but also the feel peculiar to crepe fabrics, while maintaining excellent finishing and dyeing characteristics. Further, the invention has the advantage of tending to reduce the washing shrinkage of fabrics of synthetic fibers to the minimum as compared with other fibers.

Since synthetic fibers are hydrophobic and subject to a setting effect under the influence of temperature and time and since they are less likely to swell when wetted, they do not attain an even finish or a good crepe effect when subjected to the processes available for silk and rayon. Thus it has been observed that it is difficult to manufacture crepe fabrics as good for practical use from synthetic fibers with the result that only blends of synthetic fibers and fibers of rayon, cotton or hemp have heretofore served the purpose.

As a result of our experiments, we have now found that in attaining the desired shrinkage of the above mentioned grey goods, good crepe fabric can be obtained in such a manner that the grey fabric is first treated under strong agitation or shaking in a desizing bath at a relatively low temperature below 70 0., preferably below50 C.', so as to effect sufiicient crepe shrinkage due to the physical property of high twist yarns without heat setting, and is then treated completely in a scouring bath containing a detergent at a higher temperature, say, 90-400 C. The main steps in the first stage as above described provide, firstly, shrinkage due to the physical property of high twist yarns and modification of the structure of the fabric, preventing heat setting, and, secondly, complete removal of the remnant size and the impurities by ordinary scouring. In the second stage the dry heat setting is carried out under proper tension. Further, by steam setting according to a special method there may be produced crepe fabrics of synthetic fibers which are set perfectly without uneven creping. Said steam setting is effected in such a manner that the fabric is taken up by a hollow roller with holes adapted for uniform distribution of heat and then subjected to steam treatment in an autoclave.

It should be understood that the invention is not limited to the example given hereafter and that it can be modified according to the principle thereof.

Example 1 50 denier nylon 6 yarns are given high S-twist and Z-twist at 2800 turns per meter and after a setting of the twist by heat treatment at 105 C. for 40 minutes, the yarns are given a twist at 3000 turns per meter in the op- 2,906,000 Patented Sept. 29, 1959 posite direction to the initial twist. The yarn, stretched as a result of the twisting treatment, passes in its elongated state through a 10% solution of polyvinyl alcohol and is dried to deter shrinking of the yarn temporarily. Then grey fabric is prepared by weaving 50 denier nylon 6 yarn used as warp with two sized yarns of the above prepared S-twist and Z-twist used alternately as weft. When the fabric is strongly shaken or agitated in hot water at 50. C., a part of the sizing is removed, while the width of the fabric is shrunk due to being agitated in hot water by about 35-40% to form crepe. The fabric is boiled in the bath containing detergent 2 g./l. at -100 C. for 2 hours to remove the remnant size and impurities. Then the fabric is arranged in the desired ,width, taken up by a cylinder with holes, and introduced into an autoclave. The autoclave is once placed under reduced pressure and steam at a pressure of 1 kg./cm. is supplied thereinto'to effect a steam setting of the fabric for 30 minutes. The preferred temperature of said desizing bath is of such a degree that heat setting of the stretched yarn does not occur. The proper relation of the steam temperature to the duration of time is 125 C. for 30 minutes and C. for 1.5 hours.

Example 2 Then a fabric is woven by using 50 denier nylon 66 yarn as warp and two sized yarns of the above prepared S-twist and Z-twist alternately as weft.

The grey fabric thus prepared is strongly shaken or agitated in hot water at 50 C. as indicated for Example 1, whereby a part of sizing is removed and at the same time the fabric is shrunk in its width by about 35- -40% to form crepe. Then the fabric is boiled in a bath containing detergent in a proportion of 2 g./l. at 90-100 C. for 2 hours to remove the remnant size and impurities. Thereafter, the fabric arranged in the desired width and having undergone dry heat set is taken up by a cylinder with holes and introduced into an autoclave. The latter is placed under reduced pressure, and steam is supplied thereinto at the pressure of 1 kg./cm. to effect steam setting of the fabric for 30 minutes.

Besides nylon, polyester and the like can be used as the synthetic fiber.

What is claimed is:

1. Process for the manufacture of synthetic crepe fabrics, comprising the successive steps imparting high twist, in one direction, to synthetic fibers, heat treating the twisted fibers to set the high twist in said one direction, twisting said fibers in the opposite direction beyond the point of zero twist and sizing and drying the yarn thus obtained to deter temporarily the shrinking thereof, Weaving a grey fabric having said yarn as alternate wefts therein, partly desizing said grey fabric sufiiciently to cause the latter to shrink by shrinkage of the high twist yarn therein while agitating the fabric at a temperature lower than 70 C., scouring the partly desized fabric at a temperature lower than that of which the initial high twist was set to complete the removal of sizing and impurities, shrinking the fabric widthwise, and steaming the fabric.

2. Process as in claim 1, wherein said synthetic fibers are nylon 6, and said steaming is effected at a temperature ranging between 110 and C. for a period between 1.5 and .5 hours, respectively.

3. Process for the manufacture of synthetic crepe fabrics, comprising the successive steps imparting high twisted fibers to set the high twist in said one direction, twisting said fibers in the opposite direction beyond the point of zero twist and sizing and drying the yarn thus obtained to deter temporarily the shrinking thereof, weaving a grey fabric having said yarn as alternate wefts therein, partly desizing said grey fabric sufiiciently to cause the latter to shrink by shrinkage of the high twist yarn therein while agitating the fabric at a temperature lower than 70 C., scouring the partly desized fabric at a temperature lower than that at which the initial high twist was set to complete the removal of sizing and impurities, shrinking the fabric widthwise, subjecting the fabric to dry heat to efiect the setting thereof, winding the set fabric on a cylinder with holes distributed over the surface thereof, and steaming the fabric wound on the cylinder.

4. Process as in claim 3, wherein said dry heat for setting the fabric is at a temperature of approximately 160 to 190 C.-

References Cited in the file of this patent UNITED STATES PATENTS 1,815,027 Murch July 14, 1931 2,144,676 Dreyfus Jan. 24, 1939 2,564,245 Billion Aug. 14, 1951 2,641,914 Neumager June 16, 1953 2,662,558 Mersereau et a1 Dec. 15, 1953 2,771,660 Ephland Nov. 27, 1956 2,772,191 Burleson Nov. 27, 1956 FOREIGN PATENTS 161,752 Australia Mar. 7, 1955 

